I have found a accurate load for my CZ527 22 hornet using the Berger 40gr HPV bullet. It state on the box 1:15" twist rate or better. At a averge velocity of 2995fps I get very tight five shot clover leaf groups say 3/8" at 50 yards and thats out side to out side. Increasing the the charge from 12.6 to 12.7grs drops the velocity to 2915 fps and opens the groups to 5/8".
Does the higher RPM caused by the higher velocity help make this bullet more stable or is it just in the rifles sweet spot for accuracy?
As a follow up the accuracy loads are (12.5grs AA1680, Federal 205, Rem Brass, Sierra 40gr SP, @ 2728fps) and (12.6grs Lilgun, CCI 500, Win Brass, Berger 40gr HPV @ 2995fps). Both produce 5 shot groups of .250" CC or better @ 50 yards.
Now that I am confident in these loads I will load up 50 rounds of each and more to a rifle range for some 100 & 200 yards testing.